What should I do in here?

Hint 1 of 6:

What do you normally do in a library?

Hint 2 of 6:

You read books.

Hint 3 of 6:

Examine the bookcase very carefully and, if Grace finds a book of interest,
she'll keep it.

Hint 4 of 6:

Did you notice that there are 3 sections?

Hint 5 of 6:

Examine the "Case Book" section on the far right and Grace will take Victor
Ritter's journal.

Hint 6 of 6:

Examine the middle section and Grace will take a "Lycanthropes" book and
discover a letter inside from Christian Ritter to Ludwig II.